The California Highway Patrol is looking into the inspection history of the dump truck that backed over and killed a construction employee and pinned his co-worker on Highway 17 near Scotts Valley in Santa Cruz County, a tragedy that has devastated their employer, one of California’s oldest and largest construction companies.

The CHP investigation into the death of 54-year-old Robert Gill and the serious injury to 33-year-old Stephen Whitmire is also focusing on whether the truck had working backup warning alarms at the time, according to CHP officer Trista Drake.